Waterproof, moisture vapor permeable polymers, films and coated textiles and other materials

ABSTRACT

A water vapor-permeable, waterproof adhesive polymer and a linear polyurethane-urea polymer, either alone or in combination with one another, are utilized to coat various textile materials. The compositions of these polymers as well as various methods of coating the textile materials are described.

This is a divisional application of Ser. No. 08/320,281, filed Sep. 15,1994, now U.S. Pat. No. 5,461,122, which in turn is a divisionalapplication of Ser. No. 08/014,308, filed Feb. 5, 1993 now U.S. Pat. No.5,389,430.

FIELD OF INVENTION

The present invention is directed to water vapor-permeable, waterproofpolymers as well as the use of these polymers, either alone or incombination with one another, as a coating. The invention also describesthe coated textile materials as well as methods of coating and obtainingcoated textile materials.

BACKGROUND INFORMATION AND PRIOR ART

Moisture vapor permeable backing materials having a moisture vaporpermeable pressure sensitive adhesive are disclosed by Hodgson in U.S.Pat. No. 3,645,835. The backing materials disclosed therein aresynthetic polymers which are continuous and nonpermeable to liquidwater. The adhesive materials are also permeable to moisture vapor.There is no disclosure of a discrete segmented block copolymer additiveto either the backing material polymer or the adhesive material polymerto increase the moisture vapor transmission capability.

Other materials have been suggested for use as additives to polymersused in bio-medical devices, however, not for the purpose of enhancingmoisture vapor transmission. For example, Nyilas in U.S. Pat. No.3,562,352 suggests cross-linked thermosetting polysiloxane-polyurethaneblock copolymers for use as blood contact surfaces of bio-medicaldevices. The technique disclosed therein includes fabricating the entireblood contacting device from such block copolymers or coating suchdevices with the copolymers.

Minor amounts of block copolymers including segments ofpolydimethylsiloxane and blocks of polycarbonate, polystyrene,poly-(2,6-diphenyl-1,4-phenyleneoxide), and polyamide-imide have beenblended with base homopolymers for modifying the surface properties ofthe homopolymers. Gaines, et al. in U.S. Pat. No. 3,961,122 suggestusing such surface modified polymers as thin films while Gaines, et al.in U.S. Pat. No. 3,686,355 suggest a variety of uses, including bulkuses.

Flexible, soil resistant sheet material comprising a fibrous mat coveredwith a polyurethane composition is disclosed in U.S. Pat. No. 3,423,359.The polyurethane composition contains 0.1 to 5% of a surface activeagent comprising a polyethylene oxide hydrophilic component and ahydrophobic component selected from polyalkylene oxides (exceptpolyethylene oxides), aliphatic polyesters and mixtures thereof. Nohydrophobic soft blocks such as polydialkylsiloxanes are disclosed aspart of the surface active agent.

Block copolymers useful in the treatment of fibrous materials to improvesoil release properties are disclosed in U.S. Pat. No. 3,565,845. Theblock copolymers are not mixed with a base polymer when used to treatthe fibrous materials.

Holker et al., U.S. Pat. No. 4,367,327, disclose "a monolithic,breathable polyurethane textile coating." However, the invention isdirected to a limited composition of matter claims and as a result, inactual commercial applications, there are some serious shortcomings. Itdiscloses only one polyurethane that is used both as the top coat andthe adhesive and is based only on polyethylene oxide glycol (PEO) softsegments. The use of a trifunctional isocyanate as a crosslinker is alsoclaimed. In actual applications, since the inventive medium has only thehydrophilic PEO in its backbone, the coating swells too much, especiallyduring washing. This leads to delamination from the fabric. In contrast,the present invention has two chemically different compositions as theadhesive and the top coat is based on at least three soft segments, canuse a diisocyanate as well as a polyisocyanate as a crosslinker duringcoating and, in addition, has different coating formulations involvingstabilizers, surface active additives, etc. to obtain a premiumperformance from the coated fabric.

Ward et al., U.S. Pat. No. 4,686,137, is directed only to the coatedfabric. It also uses only one polyurethane composition as the adhesiveand the top coat. It does not describe the coating formulation(crosslinkers, etc.). The coating polymer described has at least onehard segment (urea or urethane) and at least one hydrophilic (PEO) andone hydrophobic soft block (polytetrahydrofuran, also called "PTMO").Furthermore, the polymer may contain up to 2% by weightpolydimethylsiloxane (PDMS). A superficial structural similarity betweenthe structure described in Ward et al. and that in the presentapplication is deceiving as the preferred polymers in the presentapplication are cycloaliphatic 4,4-bis(isocyanatocyclohexyl)methane(HMDI) based instead of aromatic p,p'-diphenylmethane diisocyante (MDI)and the chain extender is preferably a long chain branched diamineinstead of short ethylene diamine (ED) or 1,4-butanediol (BD). Inaddition, the present invention clearly distinguishes between a top coatand an adhesive polymer and describes a well defined coatingformulation. The amount of PDMS in the top coat polymer is greater than2% by weight. The adhesive layer has reactive end groups. In addition,in actual commercial applications, the Ward system does not perform asdescribed. Even if one crosslinks the structure shown in Ward duringcoating, it still does not perform, especially due to high surfacetackiness and poor washability.

Ward et al, U.S. Pat. No. 5,120,813, is similar to the Ward '137 patent;only the claims are directed to the polymer composition and to thefilms. No improvement over the '137 system is achieved.

Uhlmann et al., U.S. Pat. No. 4,052,495 describe a method to prepare"release compositions" for non-cellular polyurethanes using low levels(0.5-5% by weight) of siloxane alkylene oxide copolymer additives. Incontrast, the present invention is directed to achieve exactly theopposite result, i.e., to permanently bond a polyurethane formulationonto a substrate.

Pechhold, U.S. Pat. No. 4,120,850 describes a polyurethane prepared byusing a "copolymer of tetrahydrofuran and ethylene oxide or propyleneoxide containing 20-70% ethylene oxide" as a soft segment together witha diisocyanate (MDI) and a diol (1,4-butanediol orhydroquinone-β-hydroxyethyl ether) as a hard segment. All reactions arecarried in bulk.

The present application, in contrast, has PTMO and PEO, together with atleast another soft segment but these segments are always separated fromeach other with a diisocyanate or a hard segment group. They are neverdirectly linked to one another. Furthermore, in terms of field ofapplications, Pechhold never mentions coated fabrics.

Matsumoto et al., U.S. Pat. No. 4,945,149, claim a coating compositionfor forming a substantially non-porous moisture permeable coating layeror fiber of a hydrophilic polyurethane resin comprising an isocyanateterminated prepolymer with a viscosity of <10,000 cps (no solvent) and acuring agent which is a diol or diamine. In contrast, the presentinvention has a high molecular weight polymer which is not isocyanateend capped. Moreover, no unreacted isocyanate is left in the presentsystem that has, if any (as in the adhesive), hydroxyl end groups.

Sakhpara, U.S. Pat. No. 4,924,214, describes a system similar toMatsumoto above. It claims an isocyanate terminated low viscosityprepolymer based on poly (alkylene oxide) glycol soft segments. No othersoft segments are utilized. No chain extenders are used or claimed. Themain concern of the invention is the viscosity of the 100% active system(no solvent is used).

Driskill et al., U.S. Pat. No. 4,925,732, describe a breathableadhesive, fabric coating prepared by using the adhesive and amicroporous poly(tetrafluoroethylene), and applications of thelaminates. The adhesive described has only one component, i.e., ahydrophilic block polyurethane consisting of PEO soft segments (Mn 600to 3500 g/mole), a hard segment consisting of a polyisocyanate and achain extender that has a molecular weight of less than 500 g/mole andoptionally a chain terminator. The laminates described are notstretchable in contrast to the laminates in the present application.

Gould et al., U.S. Pat. No. 5,120,816, describe a polyurethane ureapolymer and the application of the non-crosslinked film formed from thepolymers in the medical field. No textile coatings are described orclaimed. Moreover, the film formed in Gould is used as is, whereas inthe present invention, it is always preferred to have a fabricsubstrate.

Rautenberg et al., U.S. Pat. No. 4,761,324, describe the preparation ofa laminated elastic fabric coated with a breathable, stretchablepolyurethane film using a discontinuous adhesive. They do not have any(well defined) compositional claims on the laminate or the adhesive. Theproduct has very poor breathability as further evidenced by the need toput a very thin layer of the top coat. In addition, Rautenberg requiresthe use of a discontinuous adhesive (which is not breathable) incontrast to our solid continuous film. The present invention is notlimited to a thickness of <25 microns, either.

Waterproof, moisture vapor permeable (breathable) textile coatings havebecome a very important part of our daily lives due to the comfortprovided by these materials. Applications of these coated fabrics covera wide range of diverse fields, including but not limited to thefollowing listed below:

i. outdoor garments, such as sportswear and activewear (e.g., lightjackets, jogging suits, skiwear, etc.),

ii. heavy duty rainwear (e.g., policemen, postal carriers),

iii. industrial clean room garments (such as electronics andpharmaceutical production facilities),

iv. breathable, fluid barrier medical garments (such as surgicalgarments, bedsheets, surgical drapes, etc.),

v. protective military garments,

vi. tents and sleeping bags,

vii. wound dressings,

viii. protective marine (yacht and boat) covers,

ix. natural and synthetic leather coatings,

x. glove inserts,

xi. shoe insulation.

In principle, there are two different kinds of waterproof, breathablepolymeric textile coatings. The first types, which are also termed"microporous coatings," provide breathability due to the presence oftiny pores present in the films. These pores are too small for waterdroplets to go through, however, large enough for water vapor to pass,thus providing a waterproof, moisture permeable membrane. The secondtype, or next generation of breathables, are called "monolithiccoatings." They are solid films (not having any micropores) andtherefore they are impermeable to water. Their breathability comes fromthe specific design of their molecular structure and moleculararchitecture.

Examples of microporous, waterproof, breathable textile coatingsinclude:

    ______________________________________                                        Gore-Tex                                                                              Microporous Tetrafluorethylene                                                                    W. L. Gore, USA                                   Entrant Microporous Polyurethane                                                                          Toray, Japan                                      Ultrex  Microporous Polyurethane                                                                          Burlington, USA                                   Breathe Microporous Polyurethane                                                                          UCB, Belgium                                      Exeltech                                                                              Microporous Polyurethane                                                                          Unitika, Japan                                    Celtech Microporous Poly(amino acid)                                                                      Unitika, Japan                                    ______________________________________                                    

Examples of monolithic, waterproof, breathable textile coatings include:

    ______________________________________                                        Sympatex                                                                              Monolithic Polyester                                                                           Akzo, Netherlands                                    Witcoflex                                                                             Monolithic Polyurethane                                                                        Baxenden, U.K.                                       Bion-II Monolithic Polyurethane                                                                        Goldschmidt, Germany                                 ______________________________________                                    

In addition to being waterproof and highly moisture vapor permeable,there are many other requirements for these coatings depending on thefield of application and/or the substrates they are coated on. As anexample, when highly stretchable "Lycra-Spandex" is used as a substratefor these coatings, the coating itself must (at least) stretch as muchas "Lycra-Spandex". When applied on reusable medical garments, thecoating must be stable against washing with hot water and bleach andalso must be steam sterilizable for up to 50 cycles or more. Most of theproducts on the market, including the coatings listed above, are notsuitable for such applications.

In addition to the performance requirements of the coated fabrics, thereare also many process related requirements during the commercial coatingprocess which eventually determine the quality, aesthetics and theoverall performance of the system. The following is a list of variousperformance related requirements from these waterproof, moisture vaporpermeable coatings:

1. high water vapor transmission rate,

2. totally waterproof (also impermeable to other fluids, especiallyblood),

3. soft, dry touch,

4. good film strength (mechanical integrity),

5. good adhesion to the fabric,

6. highly stretchable,

7. good drape,

8. machine washable (including industrial washing with hot water andbleach),

9. dry cleanable,

10. good overall durability (abrasion resistance, thermal, hydrolytic,oxidative and ultraviolet stability),

11. windproof,

12. lightweight,

13. fire retardant,

14. barrier to microbes and/or other microorganisms (medicalapplications),

15. good sewability,

16. tapeability of the seams.

Process related requirements during commercial coatings:

1. Adjustable to various coating techniques

i. direct coating,

ii. transfer coating,

iii. lamination,

iv. spray coating,

v. dipping.

2. Easily compoundable with

crosslinkers or curing agents (e.g., polyisocyanates, aziridines),

pigments (e.g., titanium dioxide),

fillers (e.g., carbon black),

other specialty additives (e.g., antimicrobial agents, flameretardants),

levelling agents (e.g., silica),

surface active agents (e.g., silicone oil, fluorochemicals),

stabilizers (e.g., thermal, hydrolytic, oxidative and ultravioletstabilizers).

3. Ease of applicability to various fabrics:

woven,

non-woven,

knit,

melt blown substrates.

It is fairly difficult to combine all these properties into one coatingmaterial. For example, although microporous tetrafluoroethylene (e.g.,"GoreTex") has very good breathability and waterproofness, it is notstretchable. Similarly, the monolithic polyester ("Sympatex") suffersfrom poor stretchability. Commerically, these two materials are offeredas thin films so can only be coated onto the fabric by lamination. It isalso impossible to compound these materials with various additiveslisted above since they are offered as ready-to-laminate films.Microporous products in general also suffer from being poor barriers tovarious microorganisms. Another weakness of the presently availablewaterproof, breathable textile coatings (from respective technical datasheets and hang-tags) is the fact that they can be machine washed onlywith warm water (usually, about 40° C.) and with a mild detergent(without bleach). They can be tumble-dried at fairly low temperatures.However, as we have discussed above, especially for medicalapplications, one does not only need to wash them with hot water andwith the presence of bleach, but also to steam sterilize them attemperatures exceeding 120° C.

OBJECT OF THE INVENTION

An object of the present invention is a water vapor-permeable,waterproof adhesive polymer and a water vapor-permeable, waterprooflinear polyurethane-urea polymer.

Another object of the invention is utilizing these polymers, eitheralone or in combination with one another, as a coating. The coatedtextile materials as well as various methods of coating and obtainingcoated textile materials are other objects of the present invention.

Generally, it is an object of the present invention to improve on theart of water vapor-permeable, waterproof textile materials as hithertopracticed.

The new product described in the present application tries to combinemost of the above properties and benefits into one system. As clearlydemonstrated in the examples provided, a system superior to all otherswas achieved in overall performance. In order to achieve this, atwo-component coating system consisting of a breathable polyurethaneadhesive and a breathable polyurethaneurea top coat is prepared.

The inventive two-component coating system described here offers severalmajor advantages over others available on the market in terms of overallperformance.

First, since the polyurethanes are produced in solution they can easilybe compounded with many different additives at desired levels beforeapplying onto the fabric. These include crosslinkers and curing agents,pigments and colorants, fillers, antimicrobial agents, flame retardants,levelling agents, surface active agents, stabilizers (thermal,hydrolytic, oxidative, UV), etc. This provides a very broad flexibilityto the coater in his formulation in order to achieve specific propertiesand performance in the finished fabric. Another added benefit is thefact that the adhesive and the top coat can be formulated separatelyduring actual coating application, depending on the end use. Theseadditives do not influence the breathability of the coated fabrics.

Since both the adhesive and the top coat films are monolithic(non-porous), the coated fabrics are highly waterproof and windproof.Coated fabrics also have excellent barrier properties against otherfluids.

Films of the adhesive and the top coat materials, both, have excellentelastomeric properties and as a result excellent stretchability andrecovery. Elongation at break for these films is better than 500-600%.

An added advantage is the flexibility in the choice of the coatingprocesses that can be used in applying these materials onto variousfabrics, which include direct coating, transfer coating, lamination,dipping and spray coating. Due to this flexibility, these products canbe coated on all kinds of substrates with ease. These include woven andnon-woven fabrics, knit fabrics, melt blown substrates, leather andsynthetic leather, etc. The weight of the coating to be applied onto thefabric can also be adjusted by the coater, depending on the application.Total thickness of the film applied can be varied from a fraction of amil to several mils, as desired.

Due to their chemical structure and the molecular architecture, films ofthe top coat materials provide very soft and dry touch which is veryimportant in many applications. Inherently they are very stable againstthermal, oxidative, hydrolytic and ultraviolet degradation, which can befurther improved by the use of additives. As a result, by proper coatingformulation, they show excellent stability against repeated washing,drying, dry cleaning and even steam sterilization.

Breathable adhesive resin

Breathable adhesive resin is a segmented water vapor-permeable,waterproof polyurethane polymer consisting of at least three softsegments linked together with a diisocyanate. In some cases low amountsof a diol or diamine chain extenders is also incorporated into thesystem. Another unique feature of the adhesive resin is the fact that ithas terminal hydroxyl groups which can be used to crosslink the systemthrough the use of polyisocyanate or aziridine type crosslinkers. Thechemical structure of the polyurethane adhesive resin is given below.##STR1## where R¹ is a bivalent aliphatic or aromatic hydrocarbon groupwhich optionally may be substituted,

R² is poly(ethylene oxide) of molecular weight 400 to 8000 g/mole,

R³ is poly(tetramethylene oxide), poly(propylene oxide), polybutadieneor polyisobutylene of molecular weight 500 to 3000 g/mole,

R⁴ is a polyester glycol (such as poly(butylene adipate), poly(neopentyladipate), etc.) with a molecular weight of 500 to 3000 g/mole,

R⁵ is a bivalent aliphatic, linear or branched hydrocarbon having 2 to20 carbon atoms,

R⁶ is a linear or branched hydrocarbon chain having 2 to 20 carbon atomsor an ether having 2 to 20 carbon atoms,

R⁷ is a hydrogen or an alkyl having 1 to 4 carbon atoms,

X is an oxygen atom or ##STR2## group where R is a hydrogen atom or analkyl group having 1 to 4 carbon atoms,

Y, Z represent a hydrogen atom or a hydroxy group, with the proviso thatat least Y or Z is a hydroxy group,

(a), (b), (c), (d), and (e) represent the average repeat units in thepolymer backbone,

(a), (b), (c), and (d) are numbers up to 10,

(a), (b), and (c) each must be at least 1,

(e) is a number up to 50.

    ______________________________________                                        Typical Adhesive Resin Composition                                                      Mn                                                                            (g/mole) Preferred                                                                              Content in PU                                                                           Preferred                               Code      range    Mn       (% wt)    (% wt)                                  ______________________________________                                        PTMO (R.sup.3)                                                                          500-3,000                                                                              1,000    30-60     30-35                                   PEO (R.sup.2)                                                                           400-8,000                                                                              1,450    10-50     25-30                                   PBA (R.sup.4)                                                                           500-3,000                                                                              1,000    10-40     10-20                                   HMDI (R.sup.1)               8-25     18-22                                   Chain extender (diol or diamine) (R.sup.5)                                                        0-5         0-1                                           DGA (R.sup.6)       0.5-2.5     1.0-1.5                                       ______________________________________                                    

The three preferred soft segments, their chemical structures and theproperties they impart to the adhesive are described below: ##STR3##PTMO is a hydrophobic polyol and is mainly used to provide good dry andwet strength (i.e., good mechanical integrity and hydrolysis resistance)to the coating during washing and also during regular use. PTMO may(partially or even completely) be replaced with poly(propyleneoxide)glycol, polybutadiene glycols or polyisobutylene glycols. ##STR4##PEO is a hydrophilic polyol, an important building block for breathablepolyurethanes. ##STR5## PBA, which is a polyester polyol, is used toprovide improved adhesion properties to the system with minimalsacrifice in the hydrolytic stability. There are numerous otherpolyester polyols which can be used instead of PBA. These include butare not limited to polycaprolactone glycols, poly(neopentyladipate)glycols, poly(butylglutarate)glycols, etc. In general, thesepolyester glycols can be composed of diols with 2 to 10 carbon atomsbackbone (linear or branched) and diacids with 4 to 12 carbon atomsbackbone.

Terminal hydroxy groups through the use of an aminoalcohol

The reactive α,ω-hydroxy end groups on these adhesive polymers areobtained through the termination of the reaction system (reaction ofexcess diisocyanate) with an aminoalcohol. Due to the much higherreactivity (several orders of magnitude) of amine towards isocyanate endgroups, as soon as the aminoalcohol is added into the system, aminegroups react with the isocyanate while yielding reactive hydroxy endgroups, which can later be used for crosslinking.

The termination reaction also serves another purpose, namely, it can beused to control the molecular weight and as a result the viscosity ofthe final polyurethane(urea) system. This is quite different from theconventional methods of molecular weight control and production ofreactive hydroxy end groups in such polyurethanes, which is usuallyobtained through the use of excess diols in the initial reactionmixture.

Depending on the type of aminoalcohol used, we can obtainpolyurethane(urea)s with 2 or 4 reactive end groups, i.e., eitherα,ω-hydroxy (2 OH groups per chain) or α,ω-dihydroxy (4 OH groups perchain). Examples of aminoalcohols which give α,ω-hydroxy (one OH at eachend) polyurethane(urea)s are: ##STR6## Examples of aminoalcohols whichyield α,ω-dihydroxy (two OH at each end) polyurethane(urea)s are:

Diethanolamine

N-(3-aminopropyl)diethanolamine

Diisocyanates

During the preparation of breathable polyurethaneurea adhesive, thepreferred diisocyanates are aliphatic because of their UV stability andweatherability. These include but are not limited to:

    ______________________________________                                        4,4-bis(isocyanatocyclohexyl)methane                                                                    HMDI                                                1,6-hexamethylenediisocyanate                                                                           HDI                                                 isophorone diisocyanate   IPDI                                                ______________________________________                                    

Aromatic diisocyanates which can also be employed include, but are notlimited to:

    ______________________________________                                        p,p'-diphenylmethane diisocyanate                                                                       MDI                                                 2,4- and/or 2,6-tolylene diisocyanate                                                                   TDI                                                 m- and p-tetramethylxylene diisocyanate                                                                 TMXDI                                               1,5-naphthalene diisocyanate                                                                            NDI                                                 ______________________________________                                    

In spite of their poor UV resistance and weatherabilities, aromaticisocyanate based systems provide adhesives with good peel strengthvalues due to their increased polarities.

As mentioned above, small amounts of a flexible diol or diamine chainextender, 0-5% by weight, can also be incorporated into the system ifdesired. Diol chain extenders include, but are not limited to:1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol,propylene glycol, dipropylene glycol, etc. Diamine chain extendersinclude, but are not limited to: hexamethylene diamine,triethyleneglycol diamine, N-aminoethyl piperazine,bis(aminopropyl)piperazine, 1,3-pentanediamine,2-methylpentamethylene-diamine.

Breathable top coat polymer

Breathable top coat is a linear segmented water vapor-permeable,waterproof polyurethaneurea polymer consisting of at least 4 softsegments PTMO, PEO andpolycaprolactone-polydimethylsiloxane-polycaprolactone (PCL-PDMS-PCL)soft segments linked together with a diisocyanate (preferably aliphaticand preferably HMDI) and chain extended with a diamine (preferably 4 to10 carbon atoms and branched). The molecular weight is controlled by theuse of monoalcohols or monoamines.

Breathable top coat polyurethaneurea has the following chemicalstructure: ##STR7## where R¹ is a bivalent aliphatic or aromatichydrocarbon group which optionally may be substituted,

R² is poly(ethylene oxide) of molecular weight 400 to 8000 g/mole,

R³ is an aliphatic linear or branched hydrocarbon having 2 to 20 carbonatoms,

R⁴ is a poly(tetramethylene oxide), poly(propylene oxide), polybutadieneor polyisobutylene with a molecular weight of 500 to 3000 g/mole,

R⁵ is a polycaprolactone segment with a molecular weight of 500 to 5000g/mole,

R⁶ is an alkylenoxy group having 1 to 12 carbon atoms,

R⁷ is an alkoxy group having 1 to 20 carbon atoms or a substitutedalkylamine such as dibutylamine,

X is an oxygen atom or ##STR8## group where R is a hydrogen atom or analkyl group having 1 to 4 carbon atoms,

(a), (b), (c), (d), and (e) represent the average repeat units in thepolymer backbone,

(a), (b), (c), and (d) are numbers up to 10,

(a), (b), (c), (d) and (f) each must be at least 1,

(e) is a number up to 300, and

(f) is a number up to 10.

    ______________________________________                                        Typical Breathable Top Coat Polymer Composition                                          Mn                  Content                                                   range      Preferred                                                                              in PU  Preferred                               Code       (g/mole)   Mn       (% wt) (% wt)                                  ______________________________________                                        PTMO (R.sup.4)                                                                             500-3,000                                                                              2,000    25-50  30-40                                   PEO (R.sup.2)                                                                              500-8,000                                                                              1,450    10-50  20-40                                   PCL-PDMS-PCL                                                                              1,500-20,000                                                                            7,000     1-15   4-10                                   Butanol (R.sup.7)              0.5-1.5                                                                              0.5-1.0                                 HMDI (R.sup.1)                 10-35  20-30                                   Dytek A (R.sup.3)               3-10  4-8                                     ______________________________________                                    

Soft Segments

As we have discussed in the previous section (Breathable Adhesive), PTMOprovides good wet strength and mechanical integrity to the system. PEOagain is responsible for the breathability if used in amounts around ormore than 20% by weight. Presence of siloxane, chemically linked to thepolymer backbone, provides softer touch and good surface properties tothe resulting coating. It also has a compatibilizing effect in the finalcoating formulation (see coating procedures) where usually extra amountsof silicone fluids are added to the system to further improve theaesthetics and various other properties of the coating.

α,ω-Hydroxy terminated PCL-PDMS-PCL copolymers have the followingchemical structures: ##STR9## where (n) and (m) are variable usuallybetween 5 and 300 and (R⁶) is a short chain hydrocarbon moiety (1 to 12carbon atoms) which may also contain oxygen and nitrogen in itsstructure.

Diisocyanates

Diisocyanates which can be used in this system are the same as the onesdescribed in the adhesive formulation (both aliphatic and aromatic);however, for better UV stability and weatherability our choice willagain be an aliphatic diisocyanate and preferably HMDI (HDI and IPDI orother aliphatics are also possible). Other benefits of the aliphaticisocyanates will be fewer side reactions (more control in the reaction)and also better solubility of the hard segments formed (due to theirless rigid structure as compared with aromatic diisocyanates) whenreacted with diamine chain extenders described below, in the reactionsolvent (DMF), thus affording higher hard segment contents in thecopolymer formed and higher solids contents in the final solution.

Chain extenders

Although both diol and diamine chain extenders can be used in theformulation of our breathable top coat polyurethane(urea), our choice islong chain having 2 to 20 carbon atoms and unsymmetrical (branched)diamines. Amines are preferred due to their much higher reactivitieswith isocyanates at low temperatures (e.g., room temperature) during thereactions and also better thermal, hydrolytic and mechanical propertiesimparted to the final product due to the formation of urea linkages(versus urethanes when diols are used). Long chain branched(unsymmetrical) diamines (such as 2-methyl-pentanediamine, Dytek A fromDuPont) usually provide better solubility to the resulting copolymer,thus affording higher levels of hard segment content in the polymerbackbone and also higher solids content in the final system (solution).This will not be possible with a low molecular weight, symmetricaldiamine, such as ethylene diamine, due to its very compact and highlypolar structure, which is usually the chain extender of choice in thepatents discussed as the prior art.

Flexible diamine chain extenders include but are not limited to:

    ______________________________________                                        1,3-pentanediamine                                                                              Dytek EP      DuPont                                        2-methylpentamethylenediamine                                                                   Dytek A       DuPont                                        Triethyleneglycoldiamine                                                                        Jeffamine EDR-192                                                                           Texaco                                        N-Aminoethylpiperazine                                                                          AEP           Texaco                                        1,4-Bis(3-aminopropyl)piperazine                                                                BAPP          Texaco                                        ______________________________________                                    

Diols

Diol chain extenders include ethylene glycol, propylene glycol,1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol,dipropylene glycol, etc.

Introduction of high hard segment content in the polyurethaneureabackbone is important in the final properties and performance of thecoated fabric. Hard segment content of the polyurethaneurea usuallycontrols the mechanical properties such as modulus and ultimate strengthin addition to the thermal and hydrolytic stability of the finishedcoating.

Molecular weight control in the top coat polyurethaneurea is done byusing calculated amounts of n-butanol in the original reaction mixture.Other monofunctional alcohols, such as n-octanol or monofunctionalamines, such as dibutylamine, can also be used as molecular weightcontrolling agents.

Crosslinkers

Top coat and adhesive polymers described in the present application canbe crosslinked (cured) by using isocyanates, aziridines or melaminebased crosslinkers depending on the requirements of the field ofapplication of the coated fabrics. Isocyanate crosslinkers that can beused in the coating formulations include both aromatic and aliphaticcompounds. In terms of average functionalities, they can be difunctionalor polyfunctional (more than 2 reactive groups per chain).

The preferred crosslinkers are either difunctional or polyfunctionalaliphatic isocyanates, since they provide longer pot lives, better UVstability and weatherability to the finished coating and are colorlessor slightly yellow compounds unlike most of the aromaticpolyisocyanates, which are dark brown in color.

The amount of isocyanate crosslinker which needs to be used depends onthe isocyanate content (equivalent weight) of the compound and variesusually between 0.5 and 10 parts per hundred parts of adhesive or topcoat resin.

When aromatic isocyanates are used, due to their much higherreactivities, it may not be necessary to use a catalyst in theformulation. The experienced coater will easily be able to prepareformulations with any type of isocyanate crosslinker.

Types of icosyanates that can be used as crosslinking agents:

    ______________________________________                                        Aromatic diisocyanates:                                                                      2,4-TDI                                                                       2,6-TDI                                                                       Mixtures of 2,4 and 2,6 TDI                                                   MDI, TMXDI and                                                                NDI which can also be used during                                             the preparation of the adhesive and                                           top coat materials                                             Aliphatic diisocyanates:                                                                     HDI, HMDI, IPDI                                                Aromatic polyisocyantes:                                                                     All listed below are Miles (Bayer)                                            products:                                                                     MONDUR series:                                                                CB-60, CB-75, CB-601, CB-701, IL,                                             MR, MRS, MRS 2, CD, XP-743,                                                   XP-744, PF, E-448, E-489                                       Aliphatic polyisocyantes:                                                                    DESMODUR Series:                                                              N-75, N-100, N-751, N-3200, N-3300,                                           N-3390, Z-4370, Z-4370/2, XP-7014,                                            LS-2550, KL-2550                                               Blocked polyisocyantes:                                                                      DESMODUR Series:                                                              AP Stabil, CT Stabil, BL-3175                                  ______________________________________                                    

Equivalents of these or other isocyanate compounds from othermanufacturers can also be used in the formulations as the crosslinker.

EXAMPLE 1 Preparation of a Breathable Adhesive Resin Based on HMDI, PEO,PTMO, PBA and DGA

A reaction kettle purged with dry nitrogen and equipped with an overheadstirrer was charged with 4,698 g (4.77 mole) of PTMO, 5,133 g (3.60mole) of PEO, 2,177 g (2.04 mole) of PBA and 2,827 g (10.72 mole) ofHMDI and 3,460 g of DMF solvent. Reaction mixture was heated to 75° C.while being agitated and 2.25 g of a tin catalyst (Fomrez UL-28 fromWitco) solution in 260 g DMF was added and the reaction was started. Asthe reaction proceeded, the system was diluted with 4,675 g of MEK and4,010 g of toluene. After 3 hours of reaction a sample was removed fromthe system and analyzed for its isocyanate content. Titration showed95.7% conversion. Remaining isocyanate was capped with 97.0 g ofdiglycolamine solution in 530 g of MEK. FT-IR spectroscopy confirmed thecomplete disappearance of the isocyanate groups. The reaction mixturewas further diluted with 245 g of DMF, 345 g of MEK and 2,330 g oftoluene.

Final solution had a solids content of 48.7% by weight (determinedgravimetrically) and a viscosity of 87,000 cps at 21° C.

EXAMPLE 2 Preparation of a Breathable Adhesive Resin Based on HMDI, PEO,PTMO, PBA, BD and DGA

A reaction kettle purged with dry nitrogen and equipped with an overheadstirrer was charged with 4,697 g (4.80 mole) of PTMO, 5,131 g (3.54mole) of PEO, 2,174 g (2.04 mole) of PBA and 2,825 g (10.71 mole) ofHMDI and 3,270 g of DMF solvent. Reaction mixture was heated to 80° C.while being agitated and 2.25 g of Fomrez UL-28 solution in 90 g DMF wasadded and the reaction was started. 15 minutes later 28.5 g of BD in 265g of DMF was added into the reactor. As the reaction proceeded, thesystem was further diluted with 4,910 g of MEK and 5,820 g of toluene.Reaction was followed by FT-IR spectroscopy, monitoring the isocyanatepeak between 2,270 and 2,260 cm-1. After 3 hours of reaction, remainingisocyanate was capped with 31.5 g of diglycolamine solution in 290 g ofMEK. FT-IR spectroscopy confirmed complete reaction of the remainingisocyanate groups. The reaction mixture was further diluted with 645 gof MEK and 910 g of toluene.

Final solution had a solids content of 47.1% by weight (determinedgravimetrically) and a viscosity of 125,000 cps at 23° C.

EXAMPLE 3 Preparation of a Breathable Adhesive Resin Based on HMDI, PEO,PNA and a Diamine Chain Extender

A reaction kettle purged with dry nitrogen and equipped with an overheadstirrer was charged with 69.80 g (48.1 mmole) of PEO, 144.54 g (96.4mmole) of PNA and 71.10 g (269.7 mmole) of HMDI. Reaction mixture washeated to 80° C. while being agitated and 0.04 g of a tin catalyst(Fomrez UL-28) was added and the reaction was started. Reaction wasfollowed by FT-IR spectroscopy, monitoring the isocyanate peak between2,270 and 2,260 cm-1. After 3 hours of reaction the system was dilutedwith a mixture of 50 g DMF and 250 g MEK and then chain extended with8.70 g (118.1 mmole) of 2,2,4-trimethyl,1,6-diaminohexane solution in250 g of MEK. FT-IR spectroscopy confirmed completion of the chainextension reaction by the disappearance of the isocyanate groups.

Final solution had a solids content of 35.8% by weight (determinedgravimetrically) and a viscosity of 75,000 cps at 23° C.

EXAMPLE 4 Preparation of a Breathable Adhesive Resin Based on MDI, PTMO,PEO and PBA

A reaction kettle purged with dry nitrogen and equipped with an overheadstirrer was charged with 105.30 g (72.6 mmole) of PEO, 140.40 g (70.2mmole) PTMO, 57.05 g (54.3 mmole) of PBA, 50.90 g (202.4 mmole) of MDI.Reaction mixture was heated to 80° C. and agitated. Reaction wasfollowed by FT-IR spectroscopy, monitoring the isocyanate peak between2,270 and 2,260 cm-1. During the reaction, as the system became thicker,it was diluted with 96 g of DMF, 135 g of MEK and 155 g of toluene.Reaction mixture was cooled down after 6 hours of reaction, when IRspectroscopy confirmed the complete disappearance of the isocyanategroups.

Final solution had a solids content of 47.2% by weight (determinedgravimetrically) and a viscosity of 51,300 cps at 23° C.

EXAMPLE 5 Preparation of a Breathable Top Coat Resin

A reaction kettle purged with dry nitrogen and equipped with an overheadstirrer was charged with 3,500 g (1.78 mole) of PTMO, 2,850 g (1.95mole) PEO, 620 g (0.087 mole) of a siloxane-caprolactone copolymer(Tegomer H-Si 6440 by Goldschmidt), 63 g (0.85 mole) n-butanol, 2,820 g(10.70 mole) HMDI and 5,100 g of DMF. Reaction mixture was agitated andheated to 75° C. At this temperature a solution of 1.50 of Fomrez UL-28catalyst in 200 g of DMF was added into the reactor and the reaction wasstarted. After 1 hour of reaction a sample was taken and titrated forits isocyanate content. Temperature of the reactor was also set to 50°C. Then the system was diluted with 3,560 g of DMF. Titration showedthat 96.8% of the excess isocyanate charged into the system was stillpresent in the reaction mixture (3.2% consumed due to side reactions).727 g of Dytek A chain extender was dissolved in 1,750 g of DMF andadded into the system slowly. During the chain extension, the system wasfurther diluted with 6,655 g of DMF. At the end Dytek A addition, FT-IRspectroscopy confirmed the complete disappearance of the isocyanategroups.

Final solution had a solids content of 37.8% by weight (determinedgravimetrically) and a viscosity of 61,000 cps at 23° C.

EXAMPLE 6 Preparation of a Breathable Top Coat Resin

A reaction kettle purged with dry nitrogen and equipped with an overheadstirrer was charged with 65.00 g (32.5 mmole) of PTMO, 75.00 g (51.7mmole) PEO, 7.00 g (1.0 mmole) of a siloxane-caprolactone copolymer(Tegomer H-Si 6440 by Goldschmidt), 1.30 g (17.5 mole) n-butanol, 63.5 g(240.8 mmole) HMDI and 100 g of DMF. Reaction mixture was agitated andheated to 80° C. At this point 0.04 g Fomrez UL-28 catalyst was addedinto the reactor and the reaction was started. After 1 hour of reactionthe system was diluted with 100 g of DMF and chain extension started byslowly adding a solution of 16.38 g of Dytek A in 100 g DMF. At the endDytek A addition, FT-IR spectroscopy confirmed the completedisappearance of the isocyante groups. Then the system was furtherdiluted with 110 g of DMF to reduce the viscosity.

Final solution had a solids content of 35.5% by weight (determinedgravimetrically) and a viscosity of 57,500 cps at 23° C.

EXAMPLE 7 Characterization of Mechanical Properties and Moisture VaporTransmission Rates of Adhesive and Top Coat Polymers

In all textile coating applications, physical strength or mechanicalintegrity of the films and their moisture vapor transmission rates(MVTR) are the two most important parameters which determine the overallperformance of these coatings. The third critical property is theadhesion of these films to various substrates (i.e., fabrics), or thepeel strength of the coatings, which will be discussed in Example 8.

In actual coating applications (e.g., in textiles), the adhesive resinsare crosslinked with isocyanates or others, such as melamine oraziridine based curing agents. This increases the strength and alsoimproves the adhesion to fabric. Therefore, during our studies we havecharacterized adhesive films in the crosslinked state. In order todemonstrate the improvement in mechanical properties upon crosslinking,we also have films from Example 3 before and after crosslinking. Thecrosslinking formulation used is as follows:

    ______________________________________                                        Adhesive resin           100.0 parts                                          Crosslinker               2.5 parts                                           (Desmodur N 3390 from Miles Inc.)                                             Catalyst (Fomrez UL 28)   0.1 part                                            Toluene (dilution solvent)                                                                              40.0 parts                                          ______________________________________                                    

Films with the above composition were cast on glass plate or on arelease liner and cured for 4 hours at 120° C. before testing.

Table 1 summarizes various mechanical properties of the adhesive and topcoat films. Moisture vapor transmission rate (MVTR) data on variousfilms is provided in Table 2.

                  TABLE 1                                                         ______________________________________                                        Mechanical Properties of the Films                                                                    Ultimate                                                             Young's  Tensile    Elongation                                                Modulus  Strength   at Break                                   Sample Description                                                                           (psi)    (psi)      (%)                                        ______________________________________                                        Adhesive Film  410      1210       1025                                       (Example 1)                                                                   Crosslinked                                                                   Adhesive Film  420      1460       1120                                       (Example 2)                                                                   Crosslinked                                                                   Adhesive Film                                                                 (Example 3)                                                                   Uncrosslinked  460       720       1350                                       Crosslinked    940      4650        950                                       Adhesive Film  410      1290       1100                                       (Example 4)                                                                   Crosslinked                                                                   Top Coat Film  1900     3650        750                                       (Example 5)                                                                   Top Coat Film  1550     3400        725                                       (Example 6)                                                                   ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                        Moisture Vapor Transmission Rates (MVTR)                                      of Adhesive and Top Coat Films                                                            Thickness MVTR (g/m.sup.2 /24 hr)                                 Sample Description                                                                        (mil)     Inverted (ASTM E 96-80 BW)                              ______________________________________                                        Adhesive Film                                                                             1.2       16,000                                                  (Example 1)                                                                   Crosslinked                                                                   Adhesive Film                                                                             1.4       13,500                                                  (Example 2)                                                                   Crosslinked                                                                   Adhesive Film                                                                             1.6       14,900                                                  (Example 3)                                                                   Crosslinked                                                                   Adhesive Film                                                                             1.2       15,500                                                  (Example 4)                                                                   Crosslinked                                                                   Top Coat Film                                                                             1.2       12,300                                                  (Example 5)                                                                   Top Coat Film                                                                             1.2       14,000                                                  (Example 6)                                                                   ______________________________________                                         MVTR measurements were performed according to ASTM method E 9680 BW           (inverted cup method). Temperature was 22 ± 0.5° C. during the      measurements.                                                            

EXAMPLE 8 Transfer and Direct Coating Formulations and Procedures

Before applying the adhesive and the top coat resins onto any substrate,they are usually compounded with various stabilizers and curing agents(and other specialty fillers as required) in order to improve stability,adhesion and other properties.

Typical coating formulations for the adhesive and the top coat materialswhich are used in the preparation of samples in Examples 9 and 10 aregiven below.

                  TABLE 3                                                         ______________________________________                                        Typical Adhesive Resin Formulation for Textile Coatings                                               Parts in                                              Ingredient*             Formulation                                           ______________________________________                                        Breathable Adhesive Resin Solution                                                                    100.0                                                 (Example 1)                                                                   Polyisocyanate Crosslinker                                                                            2.5                                                   (Desmodur N 75 or N 3390)                                                     Catalyst (Fomrez UL 28) 0.001                                                 Thermal Stabilizer and Antioxidant                                                                    0.4                                                   (Irganox 1010)                                                                Hydrolytic Stabilizer   0.6                                                   (Staboxol M)                                                                  Diluent Solvent for Transfer Coating                                                                  100.0                                                 (Toluene)                                                                     Dilution Solvent for Direct Coating                                                                   25.0                                                  (Toluene)                                                                     ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Typical Top Coat Resin Formulation for Textile Coatings                                               Parts in                                              Ingredient*             Formulation                                           ______________________________________                                        Breathable Top Coat Polymer Solution                                                                  100.0                                                 (Example 5)                                                                   Polyisocyante Crosslinker                                                                             1.0                                                   (Desmodur N 75 or N 3390)                                                     Thermal Stabilizer and Antioxidant                                                                    0.4                                                   (Irganox 1010)                                                                Hydrolytic Stabilizer (Staboxol M)                                                                    0.6                                                   Silicone Oil (Abil 10000)                                                                             2.0                                                   Diluent Solvent (DMF)   50.0                                                  ______________________________________                                         *Desmodur N 75, Desmodur N 3390 and Staboxol M are products of Miles,         Inc., Pittsburgh, PA.                                                         Fomrez UL28 is a product of Witco Corporation, New York, NY.                  Irganox 1010 is a product of Ciba Geigy Corporation, Hawthorne, NY.           Abil 10000 is a product of Goldschmidt Chemical Corporation, Hopewell, VA                                                                              

Transfer Coating Procedure

In this method, using a knife over the roll system, first a calculatedamount of a solution of the top coat (sometimes also called skin)formulation (Table 4) was coated onto a release liner to yield a dryfilm of thickness between 10 to 40 microns. The solvent is evaporated inan air forced oven at 100° to 175° C. Onto this dry film, at the secondknife station, a solution of the adhesive resin (sometimes also calledtie coat) (Table 3) is applied to yield a dry film thickness of 7.5 to40 microns. While the adhesive is still tacky, the fabric and therelease paper (containing the polyurethane film) are passed through thelamination station (pressurized rubber rolls) and the polyurethanecomposite film is laminated onto the fabric. This laminate is passedthrough the second set of ovens (100° to 175° C.) to remove the solventand also cure the system. In the final station coated fabric isseparated (delaminated) from the release liner.

Transfer Coating Procedure for a Trilaminate

Trilaminate materials are sandwich structures which have fabrics on theouter sides and the breathable polyurethane layer between these twofabrics. The coating process has two steps. In the first step the fabricis coated as described above. After separation from the release liner,the coated fabric is rolled and mounted back to the second knifestation. In the second step the adhesive solution is directly applied ontop of the coated side of the fabric and then at the lamination stationit is laminated together with uncoated outer layer fabric. The system isthen passed through the drying/curing oven to remove the solvent andcomplete the curing. The trilaminate obtained is rolled and stored. Thetwo outer fabrics used in such a trilaminate structure can be the sameor different.

TRILAMINATES WITH ADHESIVE ONLY

In most of the coating applications it is necessary to use the adhesiveand the top coat polymers as described in Example 8. However, in thepreparation of trilaminate structures, which is also explained inExample 8 (using both the adhesive and top coat materials) it is alsopossible to achieve excellent results without the use of the top coatpolymer. In this case first the adhesive formulation is applied onto therelease liner, dried and partially cured, laminated onto the fabric,further dried and cured in the second set of ovens, and separated fromthe release liner. Then the coated and rolled fabric is mounted back tothe coating line and the adhesive formulation is reapplied onto thecoated side at the second knife station and then at the laminationstation this is laminated with a new roll of uncoated fabric (either thesame or a different type and make of fabric as the one used in the firstpass). The trilaminate thus produced is passed through the ovens again,to dry and completely cure the system. In general, this approach ofusing only the adhesive may provide superior adhesion and a much softerhand to the product obtained because of extremely low modulus of theadhesive used.

Direct Coating Procedure

In the direct coating process, as the name implies, the adhesivesolution is first directly applied (using a knife-over-roll system) ontothe fabric to get a thin film (10 to 40 microns). Solvent is thenremoved and the adhesive is partially cured by passing it through anoven. In the second station the top coat formulation is applied ontothis coated fabric (to yield a dry film thickness of 10 to 40 microns)and the system is dried and cured in the oven.**

Oven temperatures and line speeds in the coating lines are adjusteddepending on the design of the coating line (number of ovens andeffective oven lengths) and the type (polyester, nylon, spandex, cotton,etc.) and nature (knit, woven, nonwoven, etc.) of the fabric to becoated. This is to ensure complete drying and curing of the coatingwithout shrinking or otherwise affecting the fabric during the process.

EXAMPLE 9 Coated Fabrics, Their Moisture Vapor Transmission Rates andPeel Strengths

A wide range of coated fabrics were prepared by using direct or transfercoating procedures and tested for their performance. Table 5 lists thetypes of fabrics and the coating processes used in the preparation ofthe coated fabrics. In the transfer coating and the preparation oftrilaminates, average coating thickness for the adhesive was about 12.5microns and average thickness for the top coat was about 25 microns. Inthe direct coating the adhesive thickness was about 12.5 microns and thetop coat was about 20 microns.

Moisture vapor transmission rates were measured according to ASTM methodE 96-80 BW (inverted cup method) at 22°±0.5° C.

For peel strength measurements, a 1" polyester tape with hot meltadhesive backing was fused onto the coated side of the fabric at 325° C.by using an iron. The sample was cooled down to room temperature andaged for 24 hours. 180° C. peel strength values were obtained at roomtemperature using a Release and Adhesion Tester manufactured by TestingMachines Inc., Amityville, N.Y. Test (peel) speed was 12 minches perminute.

                  TABLE 5                                                         ______________________________________                                        Description of the Coated Fabrics, Their Moisture Vapor                       Transmission Rates (MVTR) and Peel Strength Values                            Fabric     Coating    MVTR        Peel Strength                               Description                                                                              Procedure  (g/m/2/24 hr)                                                                             (lb/2 in)                                   ______________________________________                                        Nylon Oxford                                                                             Transfer    9,400      9.90                                        200 denier                                                                    Nylon Oxford                                                                             Direct      4,500      15.30                                       200 denier                                                                    Polyester  Transfer   10,300      9.20                                        70 denier                                                                     Polyester  Transfer   --          5.40                                        (trilaminate)                                                                 Nylon Taffeta                                                                            Transfer   10,100      9.30                                        Nylon Rip Stop                                                                           Transfer   11,000      3.70                                        1.5 oz. weight                                                                Nylon Rip Stop                                                                           Direct      5,500      13.00                                       1.5 oz. weight                                                                Lycra-Spandex                                                                            Transfer    9,700      --                                          Polyester Fleece                                                                         Transfer   10,800      5.50                                        ______________________________________                                    

EXAMPLE 10 Unsupported Films of the Top Coat Polymer

In certain applications, the top coat film alone is cast on a releaseliner for later use to laminate onto a fabric or substrate of choice bythe application of heat or through the use of an adhesive as describedabove in Example 8. This is sometimes called an "unsupported film."

Preparation of the unsupported film or the film on release liner is thesame as the one described in the first step of the transfer coatingprocess of Example 8, where the top coat formulation is coated onto therelease liner and dried by passing through the ovens. In this case, inorder to get good mechanical integrity (and also depending on theapplication), a dry film thickness of 15 to 100 microns is needed. Aftercompletely removing the solvent (drying), the release liner containingthe top coat film is rolled and shipped to the user (coater) where itcan be laminated (coated) onto the desired substrate by the applicationof heat or an adhesive as described in Example 3 (transfer coating).

In some cases, depending on the requirement of the customer, it may notbe necessary to use an isocyanate crosslinker in the formulation duringthe preparation of the unsupported top coat film.

While the invention has been illustrated and described as embodied inwaterproof, moisture vapor permeable polymers, films and coated textilesand other materials, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is desired to be protected by Letters Patent is set forth in theappended claims.

We claim:
 1. A water vapor-permeable, waterproof adhesive polymer of theformula ##STR10## where R¹ is a bivalent aliphatic or aromatichydrocarbon group which optionally may be substituted;R² is a bivalentpoly(ethylene oxide) of molecular weight around between 400 to 8000g/mole; R³ is a bivalent poly(tetramethylene oxide), poly(propyleneoxide), polybutadiene or polyisobutylene of molecular weight aroundbetween 500 to 3000 g/mole; R⁴ is a bivalent polyester glycol with amolecular weight of around between 500 to 3000 g/mole; R⁵ is a bivalentaliphatic, linear or branched hydrocarbon having 2 to 20 carbon atoms;R⁶ is a bivalent linear or branched hydrocarbon chain having 2 to 20carbon atoms or an ether having 2 to 20 carbon atoms; R⁷ is a hydrogenor an alkyl having 1 to 4 carbon atoms; X is an oxygen atom or ##STR11##group where R is a hydrogen atom or an alkyl group having 1 to 4 carbonatoms; Y and Z represent a hydrogen atom or a hydroxy group, with theproviso that at least Y or Z is a hydroxy group, (a), (b), (c), (d), and(e) represent the average repeat units in the polymer backbone; (a),(b), (c), and (d) are numbers up to 10; and (a), (b), and (c) each mustbe at least 1; (e) is a number of from 1 to
 50. 2. The polymer of claim1, wherein R⁴ is poly(butylene adipate), poly(neopentyl adipate) orpolycaprolactone.
 3. A coating comprising as a principal ingredient thepolymer of the formula of claim
 1. 4. A film having a thickness of 15 to100 μm consisting essentially of a polymer of the formula of claim
 1. 5.A film having a thickness of 15 to 100 μm, consisting essentially of apolymer of the formula of claim 1 and between about 0.5 and 5% by weightof an organic polyisocyanate.